US5777332A - Automatic patient alignment during nuclear imaging body contour tomography scans - Google Patents

Automatic patient alignment during nuclear imaging body contour tomography scans Download PDF

Info

Publication number
US5777332A
US5777332A US08/689,664 US68966496A US5777332A US 5777332 A US5777332 A US 5777332A US 68966496 A US68966496 A US 68966496A US 5777332 A US5777332 A US 5777332A
Authority
US
United States
Prior art keywords
detector
patient
pitch
accordance
camera
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Fee Related
Application number
US08/689,664
Other languages
English (en)
Inventor
Albert Henry Roger Lonn
Alan Thompson
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
General Electric Co
Original Assignee
General Electric Co
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by General Electric Co filed Critical General Electric Co
Priority to US08/689,664 priority Critical patent/US5777332A/en
Assigned to GENERAL ELECTRIC COMPANY reassignment GENERAL ELECTRIC COMPANY ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: THOMPSON, ALAN, LONN, ALBERT H. R.
Priority to IL12146397A priority patent/IL121463A/en
Priority to JP9218406A priority patent/JPH10239437A/ja
Application granted granted Critical
Publication of US5777332A publication Critical patent/US5777332A/en
Anticipated expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

Links

Images

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01T—MEASUREMENT OF NUCLEAR OR X-RADIATION
    • G01T1/00—Measuring X-radiation, gamma radiation, corpuscular radiation, or cosmic radiation
    • G01T1/16—Measuring radiation intensity
    • G01T1/161—Applications in the field of nuclear medicine, e.g. in vivo counting
    • G01T1/164—Scintigraphy
    • G01T1/1641—Static instruments for imaging the distribution of radioactivity in one or two dimensions using one or several scintillating elements; Radio-isotope cameras
    • G01T1/1648—Ancillary equipment for scintillation cameras, e.g. reference markers, devices for removing motion artifacts, calibration devices

Definitions

  • This invention relates generally to medical imaging and more particularly, to aligning the image detector with the patient during nuclear tomography imaging to optimize the detector image performance.
  • gamma cameras or detectors typically are used for locating and displaying human glands and organs and associated abnormalities. Abnormalities may be represented by higher uptake or lower uptake than the surrounding tissue. More specifically, and with respect to using a gamma camera, gamma-ray-emitting tracer material is administered to a patient, and the tracer material is more greatly absorbed by the organ of interest than by the other tissues. The gamma camera generates data, or an image, representing the distribution of such tracer material within the patient.
  • a gamma camera includes a multi-channel collimator and a gamma ray detector which converts energy from the gamma ray into an electrical signal which can be interpreted to locate the position of the gamma ray interaction in the planar detector.
  • a gamma ray detector which is commonly used is an Anger gamma camera, which is described in H. O. Anger, "Scintillation Camera", Rev. Sci. Instrum., Vol. 29, p. 159 (1958).
  • Another known detector is a multi-crystal scintillation detector which has an array of small crystals coupled to an array of light detectors, which may be either photomultipliers or photodiodes.
  • Yet another known detector is a solid-state position sensitive detector which converts energy from the gamma ray into an electrical charge which can be detected by an array of contacts.
  • the Anger gamma camera includes a large scintillation crystal responsive to radiation stimuli, i.e., gamma rays emitted by the patient.
  • An array of photomultiplier tubes typically are optically coupled to the crystal.
  • the gamma rays emitted by the patient in the direction of the detector are collimated onto the crystal, and each gamma ray which interacts with the crystal produces multiple light events.
  • the multiple light events are detected by photomultipliers adjacent to the point of interaction.
  • the photomultiplier tubes in response to the light events, produce individual electrical outputs.
  • the signals from the array of photomultipliers are combined using analog and digital circuitry to provide an estimate of the location of the gamma ray event. Further analog and digital processing is used to produce more accurate position coordinates to form the acquired image.
  • a representation of the distribution of events in the crystal is generated by utilizing a matrix of storage registers whose elements are in one-to-one correspondence with elemental areas of the crystal.
  • the crystal elemental areas are identified by coordinates.
  • Each time a light event occurs in the crystal the event coordinates are identified and the register in the storage register matrix corresponding to the identified event coordinates is incremented.
  • the contents of a given register in the matrix is a number that represents the number of events that have occurred within a predetermined period of time within an elemental area of the crystal. Such number is directly proportional to the intensity of radiation emitted from an elemental area of the radiation field.
  • the number stored in the register therefore is used to establish the brightness of a display picture element corresponding to the crystal elemental area.
  • the distribution of a radiation field is displayed in terms of the brightness distribution of the display.
  • emission tomography a plurality of such images are taken at various view angles around the organ of interest.
  • transaxial tomography a series of images, or views, are taken at equal angular increments around the patient.
  • the series of views around the patient are reconstructed to form transaxial slices, that is, slices across the axis of rotation.
  • the process of acquiring the views and reconstructing the transaxial slices is termed emission computed tomography (ECT) or single photon emission computed tomography (SPECT).
  • ECT emission computed tomography
  • SPECT single photon emission computed tomography
  • CT X-ray computed tomography
  • a particular form of gantry known as a ring stand, allows the detector to rotate and also swivel (tilt) and pitch in order to be able to image various organs in different patient attitudes.
  • the ring stand can be used in connection with a patient table having its long axis parallel to the roll axis, and the detector can be brought close to the patient by adjusting the pitch axis.
  • the collimators used in known cameras and detectors have a multiplicity of holes through which gamma rays can pass.
  • the holes are separated by dense material, typically lead, which attenuates the gamma rays and absorbs a large fraction of the gamma rays which impinge on the dense material.
  • the dimensions of the openings and the thickness of the lead between the holes are selected to obtain an appropriate trade-off between resolution and sensitivity as well as to minimize the penetration through the walls of the holes.
  • the collimators are exchangeable and the operator can select a most appropriate collimator for the imaging application and the energy of the gamma rays.
  • the array of collimator holes are typically parallel with one another, but some collimators are arranged so that the openings converge at a line or point some distance from the collimator front surface so as to obtain some magnification of the patient.
  • Known multi-channel collimators used in emission imaging have an image resolution which degrades linearly with an increasing distance of the object from the collimator surface. It is beneficial, therefore, to acquire each view with the collimator as close to the patient as possible.
  • a simultaneous (or continuous) type scan is generally not feasible since the object typically is not within the center of the camera's field of view, i.e., the patient may have to be adjusted for each view thus requiring a step and shoot type scan rather than enabling a continuous scan.
  • a known ring stand described in U.S. Pat. No. 4,216,381, which is a rotating ring stand gantry, can be used with a known imaging table to perform patient body contour scanning.
  • motors and encoders on the patient table control lateral and vertical motions to move the patient close to the detector for each view, thus achieving improved resolution as described in U.S. Pat. No. 4,652,758.
  • Both U.S. Pat. Nos. 4,216,381 and 4,652,758 are assigned to the present assignee.
  • Such scanning requires careful operator setup since the table vertical and lateral motions are used both to center the organ of interest in the image and to bring the patient close to the detector. Moving a patient laterally and/or vertically during scanning also can create patient stress.
  • most known patient tables can be moved vertically for patient loading and unloading, and this vertical motion can also be used to bring the patient close to the detector at all angles. If vertical motions alone is used, the position of the patient center will shift laterally by differing amounts, depending on the roll angle and the amount of vertical shift. Such lateral image shift is undesirable since the shifting must be recorded and compensated for in the transaxial reconstruction process. Also, a lateral image shift will reduce the effective field of view and may truncate the patient image.
  • a lateral table movement may be employed so that the effective patient shift at each view can always be in the direction of the collimator holes and no lateral image shift occurs.
  • the detector rotates at a fixed radius, and vertical and lateral table motion is used to move the patient in the direction of the collimator holes so as not to introduce a lateral image shift.
  • a lateral shift is introduced so the table motion for successive views must compensate for the previous shift and the resultant motion does not shift the patient center.
  • the table must move the patient out of the way before detector rotation.
  • a large lateral motion may be required to accommodate thin patients with wide shoulders.
  • the detector orbit around the patient is achieved by rotating the detector and then moving the patient toward the detector.
  • Known methods to determine the orbit around the patient include the following methods.
  • the lateral width and anterior -posterior width of the patient and the supporting table are measured.
  • the patient is assumed to have an elliptical cross-section.
  • the orbit is calculated so that the detector is a tangent to this ellipse.
  • the measurement of the patient is typically performed using the table and gantry motions to move the detector and patient together, and then the gantry and table positions are recorded by the controlling computer.
  • the camera pitch is set, measured and saved at every view prior to acquisition. During acquisition, the camera pitch is set to the saved pitch at each angle. This method sometimes is referred to as a "learn mode" scan.
  • This method does not require any measurements prior to scanning. Rather, the operator centers the patient and sets the gantry for the first view, and at each subsequent view:
  • the camera is pitched in until a sensor on the collimator detects the patient (or table, or any other obstruction),
  • the camera is pitched out to obtain clearance to rotate
  • the sensor referred to above could be a proximity sensor consisting of a multiplicity of light beams and light sensors a small distance above the surface of the detector which would send a signal to the controlling computer when a portion of the patient or table intercepted a light beam and obstructed the passage of light from a source to a sensor.
  • This method is generally referred to as "auto sensing" since the operator does not have to take any measurements prior to scanning.
  • the above described learn mode scan requires a tedious and time consuming set-up.
  • the setup may be easier with auto sensing, there is still a potential to shift the patient center, particularly if resultant motion is employed to move the patient to a next position and a collision is detected before compensating for the lateral image shift.
  • it would be easier to use the pitch axis to reduce the distance at each view if the pitch axis is adjusted on the ring gantry, the imaged part of the patient shifts longitudinally so that the lines of data in successive views do not correspond to the same transaxial slice.
  • a method of performing a tomographic scan in which the pitch axis is adjusted to bring the detector close to the patient at every view.
  • the detector tilt is adjusted with the pitch axis so that the collimator face is parallel to the axis of rotation.
  • the patient is moved longitudinally.
  • the longitudinal axis is provided with motors and encoders to measure the longitudinal travel of the table in the direction of the roll axis.
  • the patient set-up is simple. Specifically, table height and lateral drives are used to center the organ of interest, and the pitch is used to bring the detector close to the patient. At each view, the detector pitches to come close to the patient to provide the best resolution.
  • the longitudinal shift is compensated for by longitudinal table motion so that the organ of interest can always be in the image area. Since the pitch direction is in the direction of the collimator holes, no lateral or vertical patient motion is required during a scan. Also, there is no shift in the image and no loss of field of view to be compensated for by the reconstruction process.
  • FIG. 1 illustrates the longitudinal displacement associated with camera pitch.
  • FIG. 2 illustrates reference positions used in body outline fitting.
  • FIG. 3 illustrates a series of points on the ellipse and determined by the system during acquisition.
  • FIG. 4 is a diagram illustrating a method for determining camera pitch position.
  • FIG. 5 is a diagram illustrating a method for determining the distance between the origin and the camera face.
  • the present invention in one aspect, is a method for performing a tomographic scan which allows an operator to define a non-circular orbit so that a detector can be positioned close to a patient at each view.
  • the patient to detector distance is reduced, which improves spatial resolution for the scan.
  • the table is pinned in a fixed position and the detector maintains a constant distance from its center of rotation, as it rolls to each view position.
  • the circular arc of the detector must encompass the patient and table, and for certain sections of the arc of scan, the patient's body may be several inches away from the camera.
  • the camera and table/patient are moved with respect to one another.
  • the table is pinned in position and set to lateral and vertical positions during set-up. The same lateral and vertical table positions are maintained during the scanning phase.
  • the camera is pitched in or out.
  • the camera head is tilted to achieve a tilt angle of zero degrees for all changes in pitch.
  • the central axis of the camera moves along the longitudinal axis of the table.
  • the table is extended or retracted.
  • FIG. 1 a schematic illustration of camera pitch and the associated longitudinal displacement is shown. Specifically, the camera position when pitched in and when pitched out is shown. There is a longitudinal displacement of the camera view, as represented by the displacement of T 1 and T 2 , between the pitched in and pitched out conditions. In order to keep a body part centered in the camera view for such different pitches, the body part must be moved longitudinally.
  • the present method provides the important advantages that the camera (i.e., detector) can be positioned close to the patient at each view and that the patient is moved only longitudinally, and not laterally or vertically, during a scan.
  • the camera pitch axis has a greater range than the other axes so that complex outlines can be defined. Further, after the table has been centered laterally and then positioned vertically so that the patient lies within the camera field of view, only the camera needs to be moved, during set-up, to define the required orbit.
  • the GEMS Millennium System includes a scintillation detector mounted on a rotating ring stand gantry, a number of removable collimators, a patient table, and a control computer coupled to the gantry and table for recording and controlling movement of the gantry and table.
  • the rotating ring stand detector has power drive and computer control of detector pitch and tilt and rotation (roll)
  • the table has power drive and computer control of the longitudinal axis. Additionally, for patient positioning, the table has power drive and operator control of the table vertical and lateral motion.
  • the system also includes a hand-held controller for moving the patient table and gantry during set-up and a key on the hand held controller marked ⁇ SET> which is used by the operator to indicate to the controlling computer that a set-up task is complete.
  • the collimator and some parts of the gantry are fitted with collision sensors which detect when an object meets the surface of the sensor with a pre-determined force.
  • the collimator may be fitted with proximity detectors which detect when an object approaches the face of the collimator.
  • the set-up for a patient body contour tomographic scan in accordance with the present invention requires that the operator specify the acquisition arc over which data will be taken, and the number of views (steps) that will be taken.
  • the operator may also specify a gantry starting angle or the start position may be set using the hand-held controller.
  • the system uses four reference positions. These are at gantry roll positions of -90, 0, +90 and +180 degrees. For each reference position, the system:
  • the system then waits for the operator to pitch the detector in to the patient/table outline and to mark the position by pressing the SET key on the hand-held controller.
  • the system records the positions of all axes.
  • the system uses the positions of the axes at the four marked reference positions to produce an ellipse for the upper half of the outline.
  • the lower half of the outline (the table) is fitted with a shape based on the table cross-sectional dimensions.
  • the outline could be determined with fewer or more reference positions, or with reference positions taken at other gantry angles. For example, reference positions could be taken at each view position, i.e., a learn mode.
  • the outline could also adopt an arbitrary shape by using a shape other than the ellipse. In addition, different shapes could be used for different segments of the outline.
  • the method of determining the outline could also employ an auto-sensing mechanism which allows positioning of the detector close to the outline without requiring pre-determined reference positions.
  • the first reference position is at the -90 degree gantry roll angle, which allows the operator to drive the table vertical and longitudinal axes, using the hand-held controller, to center the patient within the detector field of view. Markings on the face of the collimator help with the alignment.
  • the detector must tilt in order to keep the detector parallel with the longitudinal axis. There is also an apparent motion along the longitudinal axis which must be compensated by moving the table longitudinally.
  • the relationship between the detector pitch and the table longitudinal position is established by the system. It should be noted that during the set-up stage, the system does not move the table longitudinally as the detector pitch changes. Such movement is only required during the scanning stage.
  • the operator only needs to pitch the detector in and then press the SET key to mark the position.
  • the patient should remain centered within the detector field of view. It should not be necessary to move any other axes. However, table motion using the hand-held controller is not prevented. This allows the operator to extract the patient in an emergency, or to fine tune the centering of the patient. This means that the table vertical and lateral positions may change between marking of reference positions and these movements must be taken into account when the outline is determined.
  • the exact position of the underside of the table cradle cannot be determined.
  • the table cradle is displaced downwards (sag) due to the weight of the patient. This sag increases with patient weight and as the table cradle is extended longitudinally.
  • the +180 degree reference position must be marked to establish the position of the underside of the table cradle.
  • the system moves the gantry to the starting angle (if previously specified by the operator), or the operator moves the gantry to the start angle.
  • the system will read the current positions of the table vertical and lateral axes and store these as the base table positions to be used in the outline determination.
  • the pitch positions of the reference points must be adjusted so that they are all based on the same table vertical and lateral positions.
  • the table vertical and lateral positions are determined again and the pitch positions re-adjusted. These table vertical and lateral positions are then fixed throughout the scan.
  • the camera is assumed to rotate about its zero pitch position. This relationship typically is set when the pitch axis is characterized after installation of the system. This is not necessarily the center of the ellipse describing the orbit, since the pitch positions at opposing reference points may not always be equal.
  • the center of the ellipse is determined using the mid-points of opposing reference positions, after adjusting for table movement during set-up. Assuming that the pitch settings at the -90°, 0°, +90° and +180° reference positions are A, B, C and D, respectively, and using the coordinates based at the center of rotation of the camera, an ellipse can be constructed with center at (-A+(A+C)/2, -D+(D+B)/2) with a major axis length of (A+C) and a minor axis length of (B+D).
  • the coordinates for a series of points on the ellipse are determined using values of x ranging from 0 to its upper limit (along the semimajor axis) in the ellipse formulae (coordinates with origin at center of the ellipse).
  • each quadrant of the ellipse may be approximated using 10 points.
  • a set of points is determined, lying on the ellipse, for the upper half of the outline.
  • the coordinates of these points are all based at the center of the ellipse and must be translated to a coordinate system with the detector center of rotation as the origin.
  • the lower half of the outline is pre-defined as a set of points derived from known table cradle dimensions and based on the underside of the table.
  • these points also need to be translated to coordinates with the detector center of rotation as the origin and to take account of the table lateral position and table sag.
  • the table cradle outline is shown in FIG. 3 as a simple rectangle.
  • the camera (roll) angle for any view can be determined once the starting angle is known using the acquisition arc and the total number of views input on the acquisition card.
  • the camera pitch position needs to be determined for any given gantry roll angle.
  • the coordinates of the points defining the outline must be translated to coordinates using the camera center of rotation as the origin.
  • the angle of the camera face is known and therefore a series of lines can be defined, with that slope, passing through each point defining the outline.
  • FIG. 4 illustrates the camera rolled to an angle ⁇ along with lines parallel to the camera face, passing through two outline points (other points not shown for clarity).
  • R represents the center of rotation for the camera
  • P 1 R and P 2 R are the pitch distances for two of the outline points. These distances are measured from the origin along a line perpendicular to the camera face. These are not the distances between the origin and the outline points, which are independent of the gantry angle. In this example, P 2 R would be used as the pitch position since it is greater than P 1 R.
  • FIG. 5 illustrates determining the distance between the origin and the camera face.
  • the camera has been rolled to roll position ⁇ so that the normal, RP, to the camera face, AB, makes an angle ⁇ with the x-axis and intercepts the camera face at point P.
  • the camera face also touches point E with coordinates (x j , y j ).
  • the distance between the origin and the camera face, RP is:
  • the angle ⁇ may be determined and then the pitch distance for each outline point may be determined. If the computed value of RP is negative for some outline point, it means that the camera needs to be pitched in beyond the center of rotation to reach it, i.e., the point is on the other side of the outline.
  • the gantry roll angle ( ⁇ ) is measured in degrees with zero (and 360) being when the gantry is at the 12 o'clock position and increasing clockwise.
  • ⁇ is in radians and is calculated using:
  • the table needs to be moved longitudinally in order to maintain the same position with respect to the patient.
  • the pitch position is the vertical distance between the face of a collimator and a horizontal line running through the gantry arm pivot.
  • the pitch P 1 is the distance H 1 T 1 and in the ⁇ camera pitched out ⁇ position, P 2 is H 2 T 2 .
  • the table must be extended into the gantry ring, i.e., moved from a smaller to a larger longitudinal position.
  • the non-circular tomographic scan described above provides the important advantages that the camera (i.e., detector) is positioned close to the patient at each view and that the patient is moved only longitudinally, and not laterally or vertically, during a scan. Also, since the patient is always centered laterally and vertically within the camera field of view, simultaneous (or continuous) scanning can be performed. In addition, the camera pitch axis has a greater range than the other axes so that complex outlines can be defined. Further, after the table has been centered laterally and then positioned vertically so that the patient lies within the camera field of view, only the camera needs to be moved, during set-up, to define the required orbit.
  • the camera i.e., detector

Landscapes

  • Physics & Mathematics (AREA)
  • Health & Medical Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Biomedical Technology (AREA)
  • General Health & Medical Sciences (AREA)
  • Medical Informatics (AREA)
  • Nuclear Medicine, Radiotherapy & Molecular Imaging (AREA)
  • Optics & Photonics (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • General Physics & Mathematics (AREA)
  • High Energy & Nuclear Physics (AREA)
  • Molecular Biology (AREA)
  • Spectroscopy & Molecular Physics (AREA)
  • Nuclear Medicine (AREA)
  • Image Processing (AREA)
  • Image Analysis (AREA)
US08/689,664 1996-08-13 1996-08-13 Automatic patient alignment during nuclear imaging body contour tomography scans Expired - Fee Related US5777332A (en)

Priority Applications (3)

Application Number Priority Date Filing Date Title
US08/689,664 US5777332A (en) 1996-08-13 1996-08-13 Automatic patient alignment during nuclear imaging body contour tomography scans
IL12146397A IL121463A (en) 1996-08-13 1997-08-04 Automatic patient alignment during nuclear imaging body contour tomography scans
JP9218406A JPH10239437A (ja) 1996-08-13 1997-08-13 エミッション断層写真撮影走査システム

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US08/689,664 US5777332A (en) 1996-08-13 1996-08-13 Automatic patient alignment during nuclear imaging body contour tomography scans

Publications (1)

Publication Number Publication Date
US5777332A true US5777332A (en) 1998-07-07

Family

ID=24769417

Family Applications (1)

Application Number Title Priority Date Filing Date
US08/689,664 Expired - Fee Related US5777332A (en) 1996-08-13 1996-08-13 Automatic patient alignment during nuclear imaging body contour tomography scans

Country Status (3)

Country Link
US (1) US5777332A (ja)
JP (1) JPH10239437A (ja)
IL (1) IL121463A (ja)

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
AU666813B2 (en) * 1993-02-22 1996-02-22 Loctite Corporation Microwaveable hot melt dispenser
US6097030A (en) * 1997-09-25 2000-08-01 General Electric Company Methods and apparatus for adjusting emission imaging system detector attitude
US6603124B2 (en) * 1999-06-22 2003-08-05 Jean Maublant Apparatus for detecting and locating a radioactive source emitting gamma rays and use of said apparatus
US6723988B1 (en) * 1999-06-06 2004-04-20 Elgems Ltd. Hand-held gamma camera
US6813055B2 (en) 2001-05-30 2004-11-02 Fiberyard, Inc. Optical beam steering device
US20040263865A1 (en) * 2003-06-27 2004-12-30 Pawlak John Thomas Non-circular-orbit detection method and apparatus
US20060093093A1 (en) * 2004-11-04 2006-05-04 Chao Edward H Method and system for measuring table sag
US20060108532A1 (en) * 2004-11-25 2006-05-25 Israel Ohana Spect gamma camera with a fixed detector radius of orbit
US20070069138A1 (en) * 2005-09-29 2007-03-29 Wang Sharon X Method for reducing nuclear medicine scanning time
US20070176106A1 (en) * 2006-01-19 2007-08-02 Ge Medical Systems Israel, Ltd Methods and systems for automatic body-contouring imaging
US20070194240A1 (en) * 2006-02-21 2007-08-23 General Electric Company Methods and systems for medical imaging
US20100046817A1 (en) * 2006-09-21 2010-02-25 Koninklijke Philips Electronics N. V. Cardiac spect system with trajectory optimization

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4216381A (en) * 1979-05-10 1980-08-05 General Electric Company Structure for emission tomography scintillation camera
US4503331A (en) * 1982-04-21 1985-03-05 Technicare Corporation Non-circular emission computed tomography
JPS61142487A (ja) * 1984-12-17 1986-06-30 Hitachi Medical Corp 核医学断層撮影装置
US4645933A (en) * 1983-07-29 1987-02-24 Picker International, Inc. Emissive computed tomography
US4652758A (en) * 1984-06-04 1987-03-24 General Electric Company Nuclear imaging tomography

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4216381A (en) * 1979-05-10 1980-08-05 General Electric Company Structure for emission tomography scintillation camera
US4216381B1 (ja) * 1979-05-10 1988-09-27
US4503331A (en) * 1982-04-21 1985-03-05 Technicare Corporation Non-circular emission computed tomography
US4645933A (en) * 1983-07-29 1987-02-24 Picker International, Inc. Emissive computed tomography
US4652758A (en) * 1984-06-04 1987-03-24 General Electric Company Nuclear imaging tomography
JPS61142487A (ja) * 1984-12-17 1986-06-30 Hitachi Medical Corp 核医学断層撮影装置

Non-Patent Citations (4)

* Cited by examiner, † Cited by third party
Title
"SPECT Resolution and Uniformity Improvements by Noncircular Orbit," Stephen C. Gottschalk, David Salem, Chun Bin Lim, and Robert H. Wake, The Journal of Nuclear Medicine, vol. 24, No. 9, pp. 822-828.
Noncircular Orbits in SPECT, in Letters to the Editor, The Journal of Nuclear Medicine, p. 632, 1983. *
SPECT Resolution and Uniformity Improvements by Noncircular Orbit, Stephen C. Gottschalk, David Salem, Chun Bin Lim, and Robert H. Wake, The Journal of Nuclear Medicine, vol. 24, No. 9, pp. 822 828. *
Uniformity Artifact Reduction With Noncircular Tomographic Detector Motion, G.T. Gullberg, The Proceedings of the 30th Annual Meeting The Journal of Nuclear Medicine, p. P104., 1983. *

Cited By (21)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
AU666813B2 (en) * 1993-02-22 1996-02-22 Loctite Corporation Microwaveable hot melt dispenser
US6097030A (en) * 1997-09-25 2000-08-01 General Electric Company Methods and apparatus for adjusting emission imaging system detector attitude
US6723988B1 (en) * 1999-06-06 2004-04-20 Elgems Ltd. Hand-held gamma camera
US6603124B2 (en) * 1999-06-22 2003-08-05 Jean Maublant Apparatus for detecting and locating a radioactive source emitting gamma rays and use of said apparatus
US6813055B2 (en) 2001-05-30 2004-11-02 Fiberyard, Inc. Optical beam steering device
US7470896B2 (en) * 2003-06-27 2008-12-30 Siemens Medical Solutions Usa, Inc. Non-circular-orbit detection method and apparatus
US20040263865A1 (en) * 2003-06-27 2004-12-30 Pawlak John Thomas Non-circular-orbit detection method and apparatus
US20060093093A1 (en) * 2004-11-04 2006-05-04 Chao Edward H Method and system for measuring table sag
US7111985B2 (en) 2004-11-04 2006-09-26 General Electric Company Method and system for measuring table sag
US20060108532A1 (en) * 2004-11-25 2006-05-25 Israel Ohana Spect gamma camera with a fixed detector radius of orbit
EP1662273A2 (en) 2004-11-25 2006-05-31 Ultra Spect Ltd. SPECT gamma camera with a fixed detector radius of orbit
US7233002B2 (en) 2004-11-25 2007-06-19 Ultraspect Ltd. SPECT gamma camera with a fixed detector radius of orbit
US20070069138A1 (en) * 2005-09-29 2007-03-29 Wang Sharon X Method for reducing nuclear medicine scanning time
US7408162B2 (en) * 2005-09-29 2008-08-05 Siemens Medical Solutions Usa, Inc. Method for reducing nuclear medicine scanning time
US20070176106A1 (en) * 2006-01-19 2007-08-02 Ge Medical Systems Israel, Ltd Methods and systems for automatic body-contouring imaging
US7531807B2 (en) * 2006-01-19 2009-05-12 Ge Medical Systems Israel, Ltd. Methods and systems for automatic body-contouring imaging
US20070194240A1 (en) * 2006-02-21 2007-08-23 General Electric Company Methods and systems for medical imaging
US7408163B2 (en) 2006-02-21 2008-08-05 General Electric Company Methods and systems for medical imaging
US20100046817A1 (en) * 2006-09-21 2010-02-25 Koninklijke Philips Electronics N. V. Cardiac spect system with trajectory optimization
US8183532B2 (en) 2006-09-21 2012-05-22 Koninklijke Philips Electronics N.V. Cardiac SPECT system with trajectory optimization
US8525118B2 (en) 2006-09-21 2013-09-03 Koninklijke Philips N.V. Cardiac SPECT system with trajectory optimization

Also Published As

Publication number Publication date
IL121463A (en) 2001-08-08
IL121463A0 (en) 1998-02-08
JPH10239437A (ja) 1998-09-11

Similar Documents

Publication Publication Date Title
JP4079472B2 (ja) マルチ・スライス型計算機式断層写真法システムにおいてｘ線ビームの位置を決定するシステム
US7016456B2 (en) Method and apparatus for calibrating volumetric computed tomography systems
US9625257B2 (en) Coordinate measuring apparatus and method for measuring an object
US6206566B1 (en) X-ray apparatus for producing a 3D image from a set of 2D projections
EP1016375B1 (en) Imaging system for generating high quality images
US5291402A (en) Helical scanning computed tomography apparatus
US6292531B1 (en) Methods and apparatus for generating depth information mammography images
JP3307676B2 (ja) 回転中心とは異なる照準中心を有する２つの検出器を備えるトモグラフィ獲得方法
US5378915A (en) Apparatus and method for automatic tracking of a zoomed scan area in a medical camera system
US20060039537A1 (en) C-arm device with adjustable detector offset for cone beam imaging involving partial circle scan trajectories
US6400791B1 (en) CT device for generating tomograms of slices of a subject which are inclined relative to the longitudinal axis of a patient support
US5777332A (en) Automatic patient alignment during nuclear imaging body contour tomography scans
EP0426464A2 (en) Computerized tomographic image reconstruction method for helical scanning
EP0182529A2 (en) Radiographic system
JPH1033524A (ja) 医用画像化における画像歪みの検出及び補正の方法
JPH08509881A (ja) 区分放射線撮影走査方法および装置
US20050265523A1 (en) C-arm device with adjustable detector offset for cone beam imaging involving partial circle scan trajectories
US7636422B2 (en) X-ray CT apparatus and X-ray tube current determining method
US5657364A (en) Methods and apparatus for detecting beam motion in computed tomography imaging systems
EP0365660B2 (en) X-ray tomography apparatus having a position detector
Bronnikov Virtual alignment of x-ray cone-beam tomography system using two calibration aperture measurements
US4138611A (en) Fan beam CT apparatus with post-processing weighting of picture element signals
US5995581A (en) CR image-based positioning for X-ray CT scan
EP0200939B1 (en) Emission computed tomography apparatus
US6097030A (en) Methods and apparatus for adjusting emission imaging system detector attitude

Legal Events

Date Code Title Description
AS Assignment

Owner name: GENERAL ELECTRIC COMPANY, NEW YORK

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:LONN, ALBERT H. R.;THOMPSON, ALAN;REEL/FRAME:008517/0852;SIGNING DATES FROM 19970429 TO 19970512

FEPP Fee payment procedure

Free format text: PAYOR NUMBER ASSIGNED (ORIGINAL EVENT CODE: ASPN); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY

FPAY Fee payment

Year of fee payment: 4

REMI Maintenance fee reminder mailed
LAPS Lapse for failure to pay maintenance fees
STCH Information on status: patent discontinuation

Free format text: PATENT EXPIRED DUE TO NONPAYMENT OF MAINTENANCE FEES UNDER 37 CFR 1.362

FP Lapsed due to failure to pay maintenance fee

Effective date: 20060707